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Acquisition The process of collecting data/information from a device.

Acquisition computer The computer responsible for managing the data acquisition.

Action Actions can be one of the following: modifying variables, retrieving or storing variables from the global variables (get, put) or from disk (load, save), or executing functions.

Actions table The Actions table specifies the actions that should be executed for each marker.

ActiView Software responsible for acquiring, saving and optional transmitting data from BioSemi's Active2 EEG amplifier.

Argument A variable on which a function operates.

Audio Midi Setup See MIDI


BCI Brain-computer interface

Block Experiments are divided into different functional blocks. Each block can have a different purpose, e.g. one block for training, one for online feedback, etc.

Block file (.blk) To initialize your experiment in BrainStream, you need to compose at least one block file. Each block has its own block file, which contains or refers to all information needed to initialize the particular block.

Brainstream BrainStream is a Matlab-based toolbox that allows you to run and analyze BCI experiments in a modular way.


Common block file A special type of block file. Common block files contain or refer to information that is needed in all blocks of the experiment. For example, a common block file might contain information that is specific to the lab in which the experiment takes place.

Constants (in user defined functions) User defined functions can take constants as input arguments after the obligatory first argument 'event'.


Data segment A limited amount of data from the data stream source.

Data selection The selection of data segments from the data stream source.

DataSelection table The DataSelection table specifies which markers trigger data selection.

Debug A run mode which allows step-wise execution of programmed code. For example, when debug mode is enabled and a break point is set in Matlab, the experiment will pause at the breakpoint.

Decimation The technique of reducing the number of samples of a signal by first low-pass filtering (in order to remove aliasing effects) and then downsampling the signal.

Default variables The value that a variable will take if its content is not otherwise specified.

Dictionary table The Dictionary table translates between the marker names used in BrainStream and the source dependent marker information (type and value).


Event Every marker in the data stream instantiates a new event. During an event, one or more actions can be executed at one or more different timepoints.

Event structure a Matlab structure variable that contains all information associated with an event, for example the actions that should be executed, the variables that are required for the actions and the data that is selected during the event.

Experiment All blocks together form the experiment.

Experiment definition file (.edt or .xls) A file that contains all experiment definition tables.

Experiment definition table One of the tables that define the experiment. Includes the Actions, DataSelection, and Dictionary tables.

Experiment file (.exp) Text file that contains references to all block files and common block files of the experiment.


FieldTrip FieldTrip is a Matlab software toolbox for MEG and EEG analysis that is being developed at the Centre for Cognitive Neuroimaging of the Donders Institute for Brain, Cognition and Behaviour together with collaborating institutes. For more information see

Function A function takes input arguments and transforms them into output.


'Get' statement Statement to retrieve a copy of the current content of a user defined variable from the global variables. The name of the variable will be copied into a field of the event structure.

Global variables Variables of which the content is maintained throughout the block.

Graphical User Interface (GUI: User interface that can be used to start experiments and show feedback about performance and currently executed actions.



Initialization run file See block file



Key In the block file, settings can be specified under keys. The keys should be added to an existing or new topic and assignments must follow Matlab semantics.


'Load' statement Retrieves the content of user defined variables from disk. The content must be stored on disk with a save statement for the same variable in a previously executed block.


Markers Specify a timepoint in the data stream and may trigger BrainStream to execute certain actions or select data.

Matlab MATLABŪ is a high-level language and interactive environment that enables you to perform computationally intensive tasks faster than with traditional programming languages such as C, C++, and Fortran.

MIDI (Musical Instrument Digital Interface) A protocol which allows for communication between different computers. MIDI transmits event messages and thus no media signal such as audio.

MMM Lab The lab of the Music, Mind, Machine group at Radboud Universiteit, Nijmegen.

Modify The modify action permits users to directly change content of a global variable from the Actions table. For a modify action, the variable does not have to be retrieved from the global variables (get action), changed, and updated again (put action).




Path A path refers to the location of a folder on a hard drive. In many programs, such as Matlab, the path specifies the folders in which the programs searches for files (e.g. functions).

'Put' statement This statement updates the content of a user defined variable to the global variables. The name of the variable should exist as a field in the event structure.




'Save' statement This statement stores the content of a user defined variable to disk. A future block can retrieve this content via a load statement on the corresponding variable.

Screen Sharing A feature that allows you to access and control another remote computer by showing its screen content and directing your mouse/keyboard inputs to this device.

Sequence A sequence is defined as a succession of certain stimuli (e.g. a sequence of tones to generate an auditory evoked potential or a sequence of different motor imagery tasks). Multiple sequences form a block.

Server Computer running BrainStream.

Sessions Multiple measurements with the same subject.

Stimulus A detectable change in the environment, for example a light flash or a tone. Multiple stimuli form a sequence.

Stimulus computer The computer responsible for generating or presenting the stimuli to the subject.

String Textual information enclosed by quotes.

Structure A Matlab type variable that manages to keep a collection of (closely related) variables as sub-fields of its own.

Subject Participant in an experiment.


Time point (of actions) Moment in time relative to the onset of a marker.

Topic In the block file, keys that define settings must be organized under topics.

Trunk The trunk is the main line of a program development in a group-shared repository.


User defined function Users can write their own Matlab functions which can be called during the Experiment.

User defined variable A global variable that is defined by the user. It can be used to exchange information between different events.

User state See global variables


Variable A symbolic name given to some quantity or information. The content of a variable can change.





Topic revision: r19 - 21 Nov 2011 - 09:58:17 - MarjoleinVanDerWaal
BrainStreamDocs.DocsSectionsGlossary moved from BrainStream.DocsSectionsGlossary on 14 Nov 2011 - 10:30 by MarjoleinVanDerWaal - put it back
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